page_title: Performance and modelling of AC transmission
section_title: Nominal Π representation
hierarchical_section_title: Performance and modelling of AC transmission / Medium transmission line / Nominal Π representation
caption_attribution_description: English: Nominal Pi model of Medium Transmission line
context_page_description: Performance modelling is the abstraction of a real system into a simplified representation to enable the prediction of performance. The creation of a model can provide insight into how a proposed or actual system will or does work. This can, however, point towards different things to people belonging to different fields of work.
  Performance modelling has many benefits, which includes:
  Relatively inexpensive prediction of future performance.
  A clearer understanding of a system's performance characteristics.
  Additionally it may include, a mechanism for risk management and reduction with design support for future projects.
  A model will often be created specifically so that it can be interpreted by a software tool that simulates the system's behaviour, based on the information contained in the performance model. Such tools provide further insight into the system's behaviour and can be used to identify bottlenecks or hot spots where the design is inadequate. Solutions to the problems identified might involve the provision of more physical resources or change in the structure of the design.
  Performance modelling is found helpful, in case of:
  Estimating the performance of a new system.
context_section_description: In case of a nominal Π representation, the total lumped shunt admittance is divided into 2 equal halves, and each half with value Y ⁄ 2 is placed at both the sending & receiving end, while the entire circuit impedance is lumped in between the two halves. The circuit, so formed resembles the symbol of pi (Π), hence is known as the nominal Π (or Π network representation) of a medium transmission line. It is mainly used for determining the general circuit parameters and performing load flow analysis.
caption: Medium Transmission Line (Π representation)
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